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Biomedical subjects

S B Moore

Publications and source records attributed to S B Moore.

At least 55 records · Page 3Linked to original sources
PubMed1996

Comparison of the polyethylene glycol antiglobulin test and the use of enzymes in antibody detection and identification.

BACKGROUND: The polyethylene glycol indirect antiglobulin test for detection of red cell antibodies was compared with a proven, highly sensitive test system using papain. STUDY DESIGN AND METHODS: Parallel, prospective testing of 1508 samples with polyethylene glycol and with albumin and papain evaluated the sensitivity and specificity of polyethylene glycol. Retrospective analysis of antibody specificities was performed for the 2 years before and the 2 years after the institution of polyethylene glycol testing. RESULTS: Of 1508 prospective screens, 53 (3.5%) had discordant results: 5 were positive only in polyethylene glycol and 48 were positive only in albumin and papain. Upon antibody identification, the 5 samples that were positive only in polyethylene glycol showed 1 anti-D, 2 warm autoantibodies, and 2 false-positive results. The 48 samples that were positive only in albumin and papain showed 1 each of the following: anti-Le(b); anti-P1; anti-S; high-titer, low-avidity antibody; and cold autoantibody; there were 43 false-positive results. False-positive results totaled 12 (0.8%) with polyethylene glycol and 53 (3.5%) with albumin and papain. The retrospective analysis of antibody specificity with polyethylene glycol showed a significant increase in the detection of Fy(a) and/or Fy(b) (p < 0.0002) and Jk(b) (p < 0.0002) antibodies and a decrease in the detection of Le(a) and/or Le(b) antibodies (p < 0.0002). CONCLUSION: Polyethylene glycol retained the high sensitivity of the albumin and papain, while significantly lowering the number of false-positive results and decreasing the detection of antibodies of doubtful clinical significance.

Antibody Specificity↗
PubMed1996

Role of plasmapheresis in thrombocytopenic purpura associated with Waldenström's macroglobulinemia.

A 67-year-old man with Waldenström's macroglobulinemia had a relapse of chronic idiopathic thrombocytopenic purpura (ITP), which had been refractory to corticosteroids, splenectomy, vinca alkaloids, and high-dose intravenous gamma-globulin therapy. A biclonal gammopathy (IgM kappa and IgG lambda) was detected in his serum and was likely responsible for his refractory thrombocytopenia. He was treated with chlorambucil and prednisone. Plasmapheresis was effective in temporarily maintaining platelet counts and in decreasing morbidity until immunosuppression was completely effective against the production of the monoclonal protein. The previously reported experiences with use of plasmapheresis in patients with chronic ITP are discussed. Plasmapheresis may be of value in the treatment of selected patients with severe ITP and monoclonal gammopathy.

Aged↗
PubMed1996

Error detection and reduction in blood banking.

Error management plays a major role in facility process improvement efforts. By detecting and reducing errors, quality and, therefore, patient care improve. It begins with a strong organizational foundation of management attitude with clear, consistent employee direction and appropriate physical facilities. Clearly defined critical processes, critical activities, and SOPs act as the framework for operations as well as active quality monitoring. To assure that personnel can detect an report errors they must be trained in both operational duties and error management practices. Use of simulated/intentional errors and incorporation of error detection into competency assessment keeps employees practiced, confident, and diminishes fear of the unknown. Personnel can clearly see that errors are indeed used as opportunities for process improvement and not for punishment. The facility must have a clearly defined and consistently used definition for reportable errors. Reportable errors should include those errors with potentially harmful outcomes as well as those errors that are "upstream," and thus further away from the outcome. A well-written error report consists of who, what, when, where, why/how, and follow-up to the error. Before correction can occur, an investigation to determine the underlying cause of the error should be undertaken. Obviously, the best corrective action is prevention. Correction can occur at five different levels; however, only three of these levels are directed at prevention. Prevention requires a method to collect and analyze data concerning errors. In the authors' facility a functional error classification method and a quality system-based classification have been useful. An active method to search for problems uncovers them further upstream, before they can have disastrous outcomes. In the continual quest for improving processes, an error management program is itself a process that needs improvement, and we must strive to always close the circle of quality assurance. Ultimately, the goal of better patient care will be the reward.

Blood Banks↗
PubMed1995

Progressive apraxia in clinically discordant monozygotic twins.

OBJECTIVE: To determine disease concordancy in the first identical twin with corticobasal degeneration. The patients were 63-year-old, erythrocyte antigen-confirmed monozygotic male twins who were clinically discordant for progressive apraxia caused by corticobasal degeneration. INTERVENTIONS: Neuropsychologic and kinesiologic testing, magnetic resonance imaging, and positron emission tomographic measurements of cerebral metabolic rate for glucose. RESULTS: The affected twin had lower neuropsychologic and kinesiologic test scores than did his brother, particularly on tests sensitive to right-compared with left-hemisphere function; widespread cerebral atrophy, worst in right parietotemporal cortices; and reduced whole-brain cerebral metabolic rate for glucose, worst in right posterior cortices. The clinically asymptomatic twin had normal neuropsychologic and kinesiologic test scores but performed more poorly on tests sensitive to left- compared with right-hemisphere function; had no abnormalities on magnetic resonance imaging; and had left temporoparietal as well as mild whole-brain hypometabolism. CONCLUSIONS: Corticobasal degeneration may remain clinically discordant in identical twins after 7 years. Positron emission tomography and neuropsychologic findings suggest the possibility of a preclinical stage of corticobasal degeneration. There is generalized cortical atrophy in patients with corticobasal degeneration in addition to focal atrophy.

Apraxias↗
PubMed1995

Significance of human leukocyte antigens DR3 and DR4 in chronic viral hepatitis.

Immune mechanisms have been implicated in chronic viral hepatitis, and these may be influenced by genetic factors. To determine if disease severity in chronic viral hepatitis is associated with the human leukocyte antigens DR3 and/or DR4, 109 patients were evaluated prospectively. The frequencies of DR3 and DR4 in these patients were compared to those in 80 normal subjects. Patients with DR3 and/or DR4 had the same occurrence of severe disease as patients with other DR antigens (21% versus 30%, P = 0.3). Patients with DR3, however, had higher serum gamma globulin and immunoglobulin G levels than patients with DR4 and a greater frequency of severe disease (36% vs 12%, P = 0.046). Patients with DR4 had concurrent immunologic diseases more commonly than patients with DR3 (44% vs 9%, P = 0.005) and patients with other DR antigens (44% vs 9%, P = 0.0002). Patients with DR4 but not DR3 had severe disease less frequently than other patients (9% vs 31%, P = 0.02). The frequencies of DR3 in patients with severe disease (37% vs 18%, P = 0.06) and DR4 in patients without severe disease (44% vs 30%, P = 0.07) were different than those in normal subjects but not to a statistically significant level. We conclude that patients with DR3 and DR4 have different clinical and laboratory findings and disease severity. Patients with DR4 have milder disease than patients with other DR antigens. Disease severity, however, is not closely associated with DR3 or DR4.

Autoimmune Diseases↗
PubMed1995

Immunologic features and HLA associations in chronic viral hepatitis.

BACKGROUND/AIMS: Chronic viral hepatitis may have immunologic manifestations, and such features may reflect genetic predispositions. The aim of this study was to assess associations between immune manifestations and HLA-DR antigens. METHODS: Ninety-five patients were evaluated prospectively for immunologic features. A microlymphocytotoxicity technique was used to determine DR3, DR4, and A1-B8-DR3 phenotypes. DR antigens were also determined by restriction fragment length polymorphism in 76 patients with chronic viral hepatitis and 80 normal subjects. RESULTS: Autoantibodies were found in 59 patients (62%), and concurrent immunologic diseases were found in 22 patients (23%). Patients with antinuclear antibodies had the A1-B8-DR3 phenotype more commonly than seronegative counterparts (26% vs. 6%; P = 0.02) and had DR3 positivity more frequently than normal subjects (41% vs. 18%; P = 0.03). In contrast, patients with concurrent immunologic diseases had DR4 positivity more commonly than patients without these findings (68% vs. 27%; P = 0.001) and normal subjects (68% vs. 30%; P = 0.003). CONCLUSIONS: Patients with chronic viral hepatitis commonly have autoantibodies and/or concurrent immunologic diseases. The expression of antinuclear antibodies is associated with the A1-B8-DR3 phenotype, and the presence of concurrent immunologic diseases is associated with the DR4 phenotype. In these instances, autoimmune expression may reflect a genetic predisposition that is facilitated by viral infection or is coincidental with it.

Biomarkers↗
PubMed1995

HLA-DRB1 molecules and antigenic experience shape the repertoire of CD4 T cells.

Forces influencing the composition of the mature TCR repertoire have been well studied in the mouse. In particular, the contribution of MHC molecules in negative and positive selection events of T lymphocytes has been established. To understand whether the allelic polymorphism of HLA-DRB1 molecules can shape the human TCR repertoire, we compared the usage of TCR V beta segments in two cohorts of unrelated individuals who were selected for the expression of HLA-DRB1 alleles. To investigate the potential role of antigenic experience in shaping the TCR repertoire, we compared the usage of V beta gene elements in CD45RO- CD4+ (naive) T cells versus CD45RO+ CD4+ (memory) T cells. A correlation between V beta gene segment usage and HLA-DRB1 alleles could be demonstrated for the repertoire of the naive CD4+ T cells, suggesting a shaping force of the HLA-DRB1 allele on the peripheral TCR repertoire. While the HLA-DRB1 imposed profile in V beta distribution was maintained in CD45RO+ CD4+ T cells, it was less pronounced, indicating that antigenic experience modulates the functional TCR repertoire.

Alleles↗
PubMed1995

The differentiation of delayed hemolytic and delayed serologic transfusion reactions: incidence and predictors of hemolysis.

BACKGROUND: After differentiation of the entities of clinically detectable delayed hemolytic (DHTR) and delayed serologic transfusion reactions (DSTR), previous investigators calculated a DHTR:DSTR incidence ratio of 18:72 from a retrospective review of patients with serologic evidence of DHTR or DSTR. There are no published data on factors that may influence the occurrence of DHTR versus DSTR in a given patient. STUDY DESIGN AND METHODS: Retrospective review was conducted of 292 patients at the Mayo Clinic who, between 1980 and 1992, received a clinical diagnosis of DHTR or DSTR concurrently with a serologic diagnosis. Red cell alloantibody specificity, the activity of the patient's reticuloendothelial system, and concurrent immunosuppression were evaluated as potential predictors of the occurrence of DHTR versus DSTR in different patients. RESULTS: The incidence of DHTR or DSTR was 1 in 1899 allogeneic red cell units transfused, with a DHTR:DSTR ratio of 36:64. Alloantibody specificity was the only variable that affected the occurrence of DHTR versus DSTR at the clinical level, with the anti-Jka and anti-Fya specificities, as well as multiple coexisting specificities, significantly associated with detectable hemolysis (p < 0.05). CONCLUSION: Clinically detectable DHTRs are found to occur more commonly than previously believed when the clinical and serologic diagnoses are made concurrently and appropriate work-ups for hemolysis are ordered. The association of certain alloantibody specificities with detectable DHTRs may have implications for clinical transfusion practice.

Adult↗
PubMed1995

Blood transfusion and septic complications after hip replacement surgery.

BACKGROUND: The purpose of this study was to address some methodologic issues that might help explain the disagreement between the findings of earlier reports on the presumed association between allogeneic blood transfusion and the increased postoperative infection rates seen in orthopedic surgery patients. STUDY DESIGN AND METHODS: A retrospective review of the incidence of postoperative septic complications in 367 patients from Olmsted County, Minnesota, who underwent 420 elective total hip arthroplasties between 1986 and 1993, was conducted. The infection rates in the exposed patients (those who had perioperatively received allogeneic blood components only or allogeneic and autologous blood components) were compared with those in the untransfused patients and patients who received only autologous blood. The study had sufficient statistical power to detect a deleterious effect of allogeneic blood transfusion equal to the 2.8-fold effect observed in a recent randomized clinical trial of patients undergoing elective abdominal surgery. RESULTS: There was no association of allogeneic blood transfusion with postoperative infection (p = 0.226). Nineteen infections occurred in 201 exposed patients (9.5%), as compared to 14 infections in 219 unexposed patients (6.4%). CONCLUSION: Allogeneic blood transfusion does not increase the incidence of post-operative septic complications in patients undergoing elective total hip arthroplasty, at least to the extent that the statistical power of this study allowed the determination.

Bacterial Infections↗
PubMed1995

Blood donors who are repeatedly reactive for hepatitis C virus on enzyme immunoassay and positive on recombinant immunoblot assay: evidence of failure to identify some risk factors.

BACKGROUND: Despite the introduction of surrogate testing and subsequent antibody testing of donor blood, transmission of hepatitis C virus (HCV) still occurs. The institution from which this report originates is a medical center, and many of the blood donors have also been seen as patients at the institution. This provided an opportunity for comparison of donor questionnaire responses and medical history information and for correlation of those findings with HCV test results. STUDY DESIGN AND METHODS: HCV polymerase chain reaction (PCR) testing was performed on nine stored frozen sera from donors or former donors with previous positive results on HCV enzyme immunoassay (EIA) (first- or second-generation) and recombinant immunoblot assay (RIBA) (first- or second-generation). The medical histories were also reviewed for 22 of 23 such HCV EIA-repeatedly reactive, RIBA-positive donors and 88 randomly chosen HCV-negative donors. The lifestyle information was compared with the donors' responses on the blood donation questionnaires. The data were then correlated with available clinical and laboratory evidence of HCV transmission to transfusion recipients. RESULTS: For eight donors, there were no recipients of their blood to be assessed. For 9 of the remaining 15 donors, there were recipients who were tested for HCV. Recipients of blood from 5 of these 9 donors were repeatedly reactive for HCV; while recipients of blood from 4 donors were not. Donor PCR positivity correlated with apparent transmission (p = 0.047). Twelve of 20 HCV EIA-positive donors for whom history and questionnaires were available for comparison had at least one suggestive lifestyle or established risk factor in their medical records, while none of 88 HCV-negative controls did (p < 0.0001). The data did not indicate that paid donation correlated with failure to disclose these factors. CONCLUSION: Despite more explicit and intrusive donor questioning, it is still not possible to identify all possible risk factors at donations, though many donors who do not disclose all their risk factors are eliminated from the pool by the increasingly sensitive donor tests. As long as tests are not completely foolproof, workers must be vigilant regarding the ability to elicit complete information on a donor's risk. Further study is required to determine the best way(s) to do so.

Blood↗
PubMed1995

HLA-DQ associations in type 1 autoimmune hepatitis.

OBJECTIVE: To determine whether, in patients with type 1 autoimmune hepatitis and human leukocyte antigen (HLA) DR3 and DR4 positivity, any DQ antigen is disease-specific. MATERIAL AND METHODS: HLA class II typing was performed by restriction fragment length polymorphism in 103 patients with type 1 autoimmune hepatitis, 104 patients with chronic viral hepatitis, and 80 normal subjects. A shared association with a disease-specific DQ antigen was sought in patients with HLA-DR3, DR4, and DR3-DR4. RESULTS: Patients with HLA-DR3 and DR4 shared positivity for DQ2, DQ4, DQ5, DQ6, and DQ7, but the associations reflected established linkages or were of low frequency. Patients heterozygous for DR3-DR4 or homozygous for either DR3 or DR4 did not have a shared DQ antigen. Only the DR3-DQ2 haplotype distinguished patients with autoimmune hepatitis from normal subjects or those with chronic viral hepatitis. CONCLUSION: The DR3 and DR4 antigens are not associated with a single disease-specific DQ antigen in type 1 autoimmune hepatitis. The DR3-DQ2 haplotype is the principal risk factor for the disease at our referral center. Analyses by restriction fragment length polymorphism do not implicate a single susceptibility gene at the DQ locus.

Autoimmune Diseases↗
PubMed1995

Total potential frequency of autologous blood transfusion in Olmsted County, MN.

OBJECTIVE: To calculate the total "potential" frequency of preoperatively donated autologous erythrocyte (red blood cell or RBC) units in the entire population of patients who received transfusions in a specific US county, in a hypothetical situation in which all patients who received transfusions for elective surgical procedures (and were considered medically eligible for preoperative autologous blood donation [PABD]) predeposited a number of autologous RBCs appropriate for their procedure. MATERIAL AND METHODS: All Olmsted County residents who received RBC transfusions during 1991 and 1992 were retrospectively assessed for eligibility for PABD. Patients who were eligible to donate blood were assigned a number of autologous RBC predeposits appropriate for their scheduled procedure. Calculated total potential frequency figures for PABD were compared statistically on the basis of age, gender, and surgical service. RESULTS: Study patients were eligible for PABD in 459 of 1,038 surgical admissions. The percentage eligibility for PABD was similar across age and gender patient groups but differed across admitting surgical services. Reasons for ineligibility for PABD differed across the patient categories studied. Under the aforementioned assumption, theoretically 786 of the 8,137 RBC units transfused to all study patients (9.7%) could have been provided by PABD. CONCLUSION: From the standpoint of an entire community population, the total potential effect of PABD on the blood supply can amount to a maximum of 9.7% of all transfused units of RBCs, an upper limit that is similar across age and gender patient groups but differs across transfusing surgical services.

Adult↗
PubMed1994

Homologous blood transfusion in patients with prostate cancer: no effect on tumor progression or survival.

OBJECTIVE: To determine the effect of perioperative blood transfusions in patients with prostate cancer who underwent radical prostatectomy, we analyzed 1,785 patients with a follow-up of five years or more who were treated during a twenty-one-year period (1966 to 1987). METHODS: Patients were divided into three groups according to the number of units transfused during the perioperative period: group 1, 0 units (n = 440), group 2, 1 to 2 units (n = 746), and group 3, 3 or more units (n = 599). RESULTS: With univariate analysis, no statistically significant differences were found among the three groups in overall survival rate (71%, 75%, and 71% at ten years; p = 0.48), cause-specific survival rate (89%, 88%, and 86% at ten years; p = 0.36), or progression-free survival rate (61%, 68%, and 68% at ten years; p = 0.83). Adjusting for tumor grade, pathologic stage, and hormonal therapy using the Cox statistical model, we found no significant association between the blood-use group and overall survival rate (p = 0.45), cause-specific survival rate (p = 0.17), or progression-free survival rate (p = 0.34). The estimated relative risk and 95 percent confidence interval associated with blood transfusion (three or more units versus none) were as follows: 1.03 and 0.76 to 1.38 for total mortality, 1.56 and 0.95 to 2.56 for cause-specific death, and 1.20 and 0.91 to 1.57 for disease progression, respectively. CONCLUSIONS: According to these findings, withholding homologous blood transfusion, except for infectious precautions, should not be based on the suspicion that it can accelerate death from cancer in patients who undergo radical prostatectomy for prostate cancer.

Adult↗